The present invention relates to transflectors for use in radar and microwave antennas, and, more particularly, to a method of making precision transflectors from synthetic resin.
Transflectors are widely employed in antennas utilized in radar and microwave installations to serve as a reflector for waves of a particular polarization. Generally, such reflectors are concavo-convex structures having on the concave surface a grid of parallel fine wires disposed at closely spaced intervals which are dependent upon the frequency of the waves impinging thereon. The grid serves as a polarizer for the electromagnetic radiation and the convex surface functions as a focusing reflector for the component of radiation whose polarization is parallel to the wires.
May et al U.S. Pat. No. 3,574,258 granted Apr. 13, 1971 discloses such a transflector which is produced by securing a grating of wires to the surface of a synthetic resin sheet material which is then deformed to provide the desired concavo-convex configuration for the structure.
Ruze U.S. Pat. No. 2,930,039 granted Mar. 22, 1960 discloses a radiowave antenna in which finely divided wires are embedded in synthetic plastic bodies.
Damonte et al U.S. Pat. No. 3,340,535 granted Sep. 5, 1967 discloses an antenna in which wires are embedded between layers of synthetic resin.
Chang et al U.S. Pat. No. 4,937,425 granted Jun. 26, 1990 produces a transreflector by coating a substrate with an organometallic compound and then pyrolyzing the coating by high intensity focused light to produce the conductive grid.
Huguenin et al U.S. Pat. No. 5,455,589 granted Oct. 3, 1995 describes forming transflector by depositing a dielectric layer on a lens and then forming the metal grid on that dielectric layer.
The techniques heretofore employed attempted have involved tedious and difficult alignment of wires or deformation a closely spaced grid, or tedious techniques for removing metal to leave a grid of finely spaced conductors. Yet it is essential to the optimum operation of the transflector that the conductive stripes be parallel and uniformly spaced at small intervals. Precision alignment and spacing is difficult to obtain with such procedures and the cost of achieving a substantial degree of precision is quite high in such procedures.
It is an object of the present invention to provide a novel method for producing transreflectors which may be easily practiced to produce transreflectors with a high degree of precision for the reflective grid.
It is also an object to provide such a method for making transflectors which is relatively simple and economical.
Another object is to provide novel transreflectors in which a series of closely spaced fine lines of metal are firmly bonded to a synthetic resin body of the transflector.